Switch bailing circuit



1969 J- A. EISELE 3,461,444

SWITCH BAILING CIRCUIT FIG! INVENTOR JQHN fi. EISELE BY 2 xx 3 ATTORNEY Aug. 12, 1969 J. A. EISELE 3,

SWITCH BAILING CIRCUIT Filed Feb. 2, 1966 3 Sheets-Sheet 2 INVENTOR JOHN A. EISELE BY MM ATTORNEY United States Patent 3,461,444 SWITCH BAILING CIRCUIT John A. Eisele, Oxon Hill, Md, assignor to the United States of America as represented by the Secretary of the Navy Filed Feb. 2, 1966, Ser. No. 524,975 Int. Cl. G081) /00; H04q 1/00; H051) 39/00 US. Cl. 340-332 5 Claims The present invention is directed to a plurality of interconnected electrically operable switches arranged so that when a particular switch is selected and pushed any previously selected switch is released.

There are many arrangements of switches, commonly called switch bailing circuits, that act to release any previously selected switch when another switch is selected. For example, the more expensive automobile radio using individual push-button selectors as the station locators have such switch bailing arrangements, although they are mechanically operable. However, such arrangements have not accentuated the need for maximum space utilization since space is usually not a limiting factor in the design of these switching arrangements. Another important consideration in the design of switching circuits is the reduction in the number of components to perform a given operation. Relays, for example, are relatively expensive (in addition to causing heat) and, consequently a reduction in the number used in a given circuit is a prime requisite in the design of any given circuit. The need for circuit arrangements of this type is greatly increased due to the recent advancements in the field of space technology where problems involving size and weight of the satellites are prime considerations in the design of the booster-s required to launch them. For example, control panels in such satellites require switch bailing circuits having less components and dissipating less heat while performing at least as many operations as conventional circuitry.

The general purpose of this invention is to provide a switch bailing circuit which embraces all the advantages of similarly employed devices and possesses none of the aforedescribed disadvantages. It should be pointed out that although the disadvantages previously mentioned in prior switch bailing circuits, namely, size, expense and heat, have been eliminated by the unique arrangement of the electrical components in the instant invention, no adverse effects have been encountered as a result thereof, yet all of the attendant advantages have been retained.

To attain this, the invention provides a switch bailing circuit comprising a load impedance connected in series with a first plurality of two-positioned switches in the normal position, each switch being movable relative to a fixed surface by a spring biased, force operated plunger, the plunger being further connected to a movable armature and at least a second plurality of two-position output switches. Connected in the second position of each of the first plurality of switches is a diode in series with a holding coil the latter having its other side connected to the output of the respective first switches. Also connected in the second position of each of the first switches is an indicator lamp having its other side connected to ground the entire arrangement acting to provide a switch bailing circuit wherein when any switch is pushed a previously pushed switch will be released and wherein the indicator lights may be wired independently of the holding coils. In a second embodiment of the invention, there is shown an indicator circuit arrangment using the fundamental circuitry of the invention, while permitting simultaneous indications of malfunctioning in the output circuit controlled by the basic switching device.

An object of the present invention is the provision of a bailing circuit including a plurality of switches wherein p r: 3,461,444 Ice Patented Aug- 1969 when one switch is pushed any previously energized switch is released.

Another object of the invention is the provision of an electrical bailing circuit arrangement using a reduced number of components to perform the same number of operations as previously available circuits.

Another object of the invention is the provision of a switch bailing circuit having an arrangement of electrical switches using blocking diodes as current limiters thereby eliminating the need for more expensive relays while providing a greater flexibility in the utilization of a given number of electrical components.

Still another object of the invention is the provision of a unique circuit arrangement wherein the indicator lamps may be pre-wired to ground.

Yet another object of the invention is the provision of a switch bailing circuit wherein the lights may be wired independently of the holding coils so as to facilitate installation of the lights to the switch bailing circuit.

Another object of the invention is to provide a switch bailing circuit including an indicator circuit for indicating visually the normal operating condition and a malfunctioning condition using separate lamps each connected to ground.

With these and other objects in view, as will hereinafter more fully appear, and which will be more particularly pointed out in the appended claims, reference is now made to the following description taken in connection with the accompanying drawing in which:

FIG. 1 shows the circuit diagram of the invention in an inactivated position;

FIG. 2 shows the circuit diagram of the invention with the first button pushed to the closed position;

FIG. 3 shows the circuit diagram of the invention with the second button pushed to the closed position;

FIG. 4 shows the circuit diagram of the device with the third button pushed to the closed position; and

FIG. 5 shows the circuit of the invention with an alternate arrangement of the indicator lamp circuit.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several figures, there is shown in FIG. 1 a main switch 3 having one side connected to terminal 11, and another side connected to resistor 7, the latter acting as a load resistance together with main indicator lamp 5 to prevent a short circuit when only the main switch 3 is pressed. Terminal 10 connects to movable switch blade 17 in electrically operated device 2. A supply of DC. voltage is applied at terminals 10, 11 was to prvoide a source of current for the entire circuit. Lamp 5 provides a visual indication as to when current is flowing through the circuit.

Switch operated device 2 comprises push-button 13 mounted on fixed member 15 with spring 14 acting to bias push-button 13 away from member 15. A plunger 35 is attached to the lower end of button 13 and acts as a rigid connecting rod to move armature 18 of holding coil 22 in addition to gauging the 2-position output switches 24, 28 and 32 together. Output switches 24, 28 and 32 act to make and break the respective output terminal circuits. For example, in one position of switch 24, terminals 23 and 25 are connected together while terminal 26 is open. In like manner terminals 27 and 29 are connected together when switch 28 is in one position and terminal 30 is open, and terminals 31 and 33 are connected when switch 32 is in one position while terminal 34 is open. Connected to the second position of switch blade 17 is a grounded indicator lamp 20, and a forward positioned diode 21 in series with holding coil 22, the latter of which is connected to the terminal side 16 of switch 17.

Similarly, switch operated device 4 is comprised of push-button 43 mounted on fixed member 45 with spring 44 acting to bias push-button 43 away from member 45. A plunger 65 is attached to the lower end of button 43 and acts as a rigid connecting rod to move armature 48 of holding coil 52 in addition to gauging the 2-position output switches 54, 58 and 62 together. Output switches 54, 58 and 62 act to make and break the respective output terminal circuits. For example, in one position of switch 54, terminals 53 and 55 are connected together while terminal 56 is open. In like manner terminals 57 and 59 are connected together when switch 58 is in one position and terminal 60 is open, and terminals 61 and 63 are connected when switch 62 is in one position while terminal 64 is open. Connected to the second position of switch blade 47 is a grounded indicator lamp 50, and a forward positioned diode 51 in series with holding coil 52, the latter of which is connected to the terminal side 46 of switch blade 47.

Switch operated device 6, like devices 2 and 4 comprises a push-button 73 mounted on fixed member 75 with spring 74 acting to bias push-button 73 away from member 75. A plunger is attached to the lower end of button 73 and acts as a rigid connecting rod to move armature 78 of holding coil 82 in addition to ganging the 2- position output switches 84, 88, and 92 together. Output switches 84, 88 and 92 act to make and break the respective output terminal circuits. For example, in one position of switch 54, terminals 83 and 85 are connected together while terminal 86 is open. In like manner terminals 87 and 89 are connected together when switch 88 is in one position and terminal 90 is open, and terminals 91 and 93 are connected when switch 92 is in one position while terminal 94 is open. Connected to the second position of switch blade 77 is a grounded indicator lamp 80, and a forward positioned diode 81 in series with holding coil 82, the latter of which is connected to the terminal side 76 of switch blade 77.

FIGURES 2, 3 and 4 show the device with buttons 13, 43 and 73 respectively pushed in each of the illustrations of the circuit shown in the figures. Apparent from the FIG- URES 2-4 is the fact that upon pushing any of the buttons 13, 43 and 73, any previously pushed button will be released, the device accordingly acting as bailing circuit.

Turning to FIGURE 5 where the basic device is shown with an alternate embodiment of the light indicator circuit, the circuit comprising all circuitry connected to terminals 19, 49 and 79 enclosed in the dotted area 100. The remaining circuitry is identical to that shown in FIGURE 1 (excluding indicator lamps 20, 50 and 80) with the same reference numerals being used for identical parts. This modification of the light indicator circuit enclosed in dotted area is designed to be used in connection with a circuit breaking means 120 for switching the electrical ground from terminal 121 to terminal 122 by mechanically moving switch blade 123. The circuit breaking means 120' may be any form of electromechanical transducer for sensing physical variables such as temperature, air pressure, water pressure, electrical failure, etc., at remote locations from the indicator device.

Terminals 121 and 122 are connected to points 113 and 114, respectively and each acts as a common connecting point to respective sets of indicator lamps 102, 103, and 108, 109 and 111. Diodes 101, 104, 106, 107, and 112 serve to permit current to flow in the desired direction in each of the indicator circuits where they are located.

Although the modification is shown with switches in the inactivated position only, obviously the circuit will operate in similar manner to the circuits shown in FIGS. 2-4 when respective buttons 13, 43 and 73 are pushed.

Operation A typical operation of the device as illustrated in FlGS. 1-4 will include the following: in the inactivated position the main switch 3 shown in FIG. 1 will be open and indicator light 5 will be off indicating that no current is flowing through the circuit thus preventing a drain of the source of supply. All three button operated plungers 35, 65 and 95 will be in an upward position thereby causing switch blades 17, 47 and 77 to contact respective terminal sides 16, 46 and 76 so as to provide a completed circuit therebetween. Thus when main switch 3 is closed current will flow between inputs 10, 11 and lamp 5 will indicate to the viewer that the device is energized. Of course, output switches 24, 54, 84 and 28, 58, etc., will be in one position which could be either an off or on position depending on the needs of the particular load being used.

Upon pushing button 13 switch blade 17 closes the circuit between input terminal 10 and terminal 19 thus causing current to flow through forward biased diode 21 and holding coil 22 and through indicator lamp 20. Once pushed, holding coil 22 will retain armature 18, which is further attached to plunger 35, in position. Button 13 will remain down and output switches 24, 28 and 32 will re main closed. While current Will be available to flow towards terminals 49 and 79 in the respective inactivated switching units, none will flow due to the high impedance olfered by back biased diodes 51 and 81.

Next pushing button 43 or switch operated device 4 causes (1) the circuit between terminal 19 and input terminal 11 to be temporarily broken during the interval of time required for blade 47 to travel from terminals 46 and 49 which further causes button 13 to return to its deenergized position, (2) the circuit between input terminal 10 and terminal 49 to be completed so as energize holding coil 52 and indicator light 50, and (3) the two position switches 47, 54, 58 and 62 to be retained in their second position due to energization of holding coil 52.

Pushing button 73 will cause switch operated device 6 to act similar to the operation of device 4 when button 43 is pushed, as discussed above. Although buttons 13, 43 and 73 are illustrated as pushed in a particular sequence, any button may be pushed once main switch 3 is closed, and upon pushing another button any previously pushed button will be released as discussed above. Further, although only three switch operated devices are shown any number greater than one may be used. As a matter of visual convenience different color lights may be used as the indicator lights illustrated and, or, a central panel having the indicator lights in a particular order may be used.

Turning now to the operation of the device having an alternate arrangement of indicator lights for use in connection With transducer activated switch 123 it may be seen that, with switch 3 closed, upon pushing button 13 switch blade 17 closes the circuit between input terminal 10 and terminal 19. The current flowing through forward biased diode 21, etc. will cause the circuit to operate in identical manner discussed in connection with FIG. 2. The current flowing through forward biased diode 101 and lamp 102 will flow to ground when switch blade 123 is connected to terminal 121. Thus indicator lamp will be lighted visually indicating that holding coil 22 is properly positioned and that no abnormal condition has been detected by transducer 120. If transducer senses an abnormal condition switch blade 123 will be mechanically moved to its second position at terminal 122. Since the circuit between ground and common point 114 is completed when switch blade 123 is in this position current will flow through forward biased .diode 107 and lamp 108 so as to give a visual indication of the condition detected.

Pushing buttons 43 or 73 will cause the respective circuitry to operate in similar fashion to the circuit as discussed above. Regardless of which button is pushed respective lights 109 and 111 will be connected so as to give a visual indication of the position of switch blade 123.

For purposes of illustrating a practical use of the latter circuit while not limiting same, transducers 120 may be a bi-metallic temperature sensor designed to detect temperatures above a critical level. Thus, if button 13 is pushed, after having pushed main switch 3, and the temperature goes above a critical level switch blade 123 will be moved to its second position due to the movement of the bismetallic element of transducer 120 thereby lighting lamp 108 giving a visual indication that the circuits connected to output switches 24, 28 and 32 should be disconnected due to malfunctioning.

Although switch 123 is shown movable by transducer unit 120, it is within the scope of this invention to use any means desirable to move the switch as, for example, a hand operated throw switch, etc. Also, while conventional diodes are shown as the current limiting devices any device acting as a unidirectional current control is suitable for use in the device without departing from the scope of the invention. Finally, the particular arrangement of the outputs of each switch is merely illustrative and can vary in accordance with the environment in which the switch is used.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention.

What is claimed and desired to be secured by Letters Patent of the United States is.

1. A switch bailing circuit comprising:

a plurality of switch means each including a respective movable blade, each of which is selectively connectable to either of a pair of respective terminals, said blades being normally biased for connection to one of said respective terminals in a first position and being in series connection in said first position,

input terminals for applying energization current to said switch means,

an respective unidirectional current limiting means for each of said switch means, each of said unidirectional means having its forward-biased end connected to the second terminal of said pair of terminals of each of said switched means,

a holding coil connected at one of its ends to the backbiased side of each of said unidirectional means in series therewith, the other side of said holding coil connected to said one terminal of its respective switch,

a respective plunger mechanically connected to each of said switch blades, and

a respective armature associated with each of said plungers and situated to be operated by its respective holding coil, such that when energization is applied to said input terminals when any switch is initially moved from engaging its said one terminal to its said second terminal, any switch subsequently moved from its said one terminal to its said second terminal will release the previously pushed switch.

2. The device as defined in claim 1 further including:

a respective indicator lamp connected to each of said respective second terminals, said indicator lamp being further connected to electrical ground and associated with said respective switch means such that when any of said respective switch blades is moved to connect its second terminal the respective indicator lamp associated therewith will light,

a main indicator lamp having a substantial impedance connected in series between said input terminals, and

a main switch connected in series with said main indicator lamp such that upon closing said main switch a complete circuit is formed between said input terminals.

3. The device as defined in claim 1 further including,

a respective set of ourput switches associated with each of said plungers so as to be selectively controlled thereby.

4. The device as defined in claim 1 wherein,

the bias means for the respective switch blades is a spring,

a respective unidirectional current limiting means is a diode,

the holding coil is a solenoid, and

each of said indicator lamps are colored different shades so as to facilitate visual detection of the position of said respective switch blades, and

further including,

a respective push-button connected to one end of each of said respective plungers.

5. The device as defined in claim 1 further including a visual indicator circuit comprising:

a first set of respective current limiting means connected on their forward biased side to each of said respective second terminals,

a second set of respective current limiting means connected on their forward biased side to each of said respective second terminals,

a respective indicator lamp connected to each of the current limiting means of said sets of current limiting means on their back biased side,

each said indicator lamps connected to said first set of current limiting means being connected to a common point, and

each of said indicator lamps connected to said second set of current limiting means being connected to a common point such that either sets of current limiting means will permit current to flow therethru when the respective set of indicator lamps is electrically grounded.

References Cited UNITED STATES PATENTS 2,971,135 2/1961 Ebert 340-332 3,150,238 9/1964 Carter 340-476 THOMAS B. HABECKER, Primary Examiner U.S. Cl. X.R. 

1. A SWITCH BAILING CIRCUIT COMPRISING: A PLURALITY OF SWITCH MEANS EACH INCLUDING A RESPECTIVE MOVABLE BLADE, EACH OF WHICH IS SELECTIVELY CONNECTABLE TO EITHER OF A PAIR OF RESPECTIVE TERMINALS, SAID BLADES BEING NORMALLY BIASED FOR CONNECTION TO ONE OF SAID RESPECTIVE TERMINALS IN A FIRST POSITION AND BEING IN SERIES CONNECTION IN SAID FIRST POSITION, INPUT TERMINALS FOR APPLYING ENERGIZATION CURRENT TO SAID SWITCH MEANS, AN RESPECTIVE UNIDIRECTIONL CURRENT LIMITING MEANS FOR EACH OF SAID SWITCH MEANS, EACH OF SAID UNIDIRECTIONAL MEANS HAVING ITS FORWARD-BIASED END CONNECTED TO THE SECOND TERMINAL OF SAID PAIR OF TERMINALS OF EACH OF SAID SWITCHED MEANS, A HOLDING COIL CONNECTED AT ONE OF ITS ENDS TO THE BACKBIASED SIDE OF EACH OF SAID UNDIRECTIONAL MEANS IN SERIES THEREWITH, THE OTHER SIDE OF SAID HOLDING COIL CONNECTED TO SAID ONE TERMINAL OF ITS RESPECTIVE SWITCH, 